Northern Territory in March 2014: A taste of the dry season in the north

March 2014 saw no monsoon activity in a month that is usually fairly wet across the tropical north. As a result rainfall totals were among the lowest on record for most Top End locations. A lack of cloud cover allowed daytime temperatures to rise, while dry air allowed overnight temperatures to lower.

Tropical cyclone Gillian moves across the water to the north, but did not affect the NT coastline

Tropical cyclone Gillian

Tropical cyclone Gillian began as a tropical low over the Arafura Sea on 6 March in the southeastern Arafura Sea, about 330 km northeast of Gove. It remained slow-moving until overnight on 7 March, when it began moving towards far north Queensland, while developing. On 8 March it first reached tropical cyclone strength and was named tropical cyclone Gillian as it continued to track towards the Gulf of Carpentaria and into a favorable atmosphere. Whilst in the Gulf of Carpentaria, it weakened and was downgraded to below tropical cyclone intensity just before it crossed the west coast of the Cape York Peninsula during 10 March. On 11 March the system remained near-stationary for 24 hours before moving southwards over land until the morning of 12 March and then westwards and back over water on 13 March. The system then took a northeasterly path and re-intensified to a category 1 cyclone on 14 March. Gillian then tracked northwards over the central Gulf of Carpentaria with no immediate threat to the Gulf coast, however, again the system encountered unfavorable atmospheric conditions and was downgraded once more to below tropical cyclone intensity on 15 March. Ex-tropical cyclone Gillian then moved steadily northwest across the Arafura Sea until colliding with Timor on 18 March. Just below tropical cyclone strength, the tropical low crossed East Timor on the 18th and followed along the southern Flores Sea and the Lesser Sunda Islands on 19 to 20 March. The low shifted south over Bali on 20 March but continued to track west over the Indian Ocean. On 21 March, the low intensified again to a category 1 system and was again at tropical cyclone status. Shortly after passing near Christmas Island on 22 March, tropical cyclone Gillian turned south and strengthened further. The storm reached a maximum strength on 24 March with mean winds of about 198 km/h (category 5) while over the Indian Ocean. Tropical cyclone Gillian then weakened and dissipated on 26 March while moving west away from Australia.

Very dry March for the NT

The Northern Territory as a whole saw the driest March since 2009 with only 54.3 % of normal March rainfall. Many locations in the Alice Springs District did not measure any rainfall this month. Several sites, including Adelaide River, Palmerston (Yarrawonga) and Yulara had their lowest total March rainfall on record. Darwin Airport, with only 92.2 mm, had its driest March in 36 years and the second driest March on record. Alice Springs Airport received only 1.4 mm of rainfall, compared to the long-term average is 31.8 mm.

Not everywhere was dry. Several coastal locations had a few large rainfall events in the month. The wettest single day was at Cape Wessel with 206.0 mm on the 8th as pre-tropical cyclone Gillian moved toward the Gulf of Carpentaria. Cape Wessel ended the month with 365.6 mm, making it the wettest location in the NT for March 2014 and the only station in the Arnhem region to see above average rainfall. A few showers and storms moved across the Victoria River and the Barkly Districts within the first few days of the month such that some places, including Bradshaw Homestead, Kidman Springs and Brunette Downs ended the month near, or slightly above average for March.

Average to above average maxima for the NT

Most of the Northern Territory experienced close to average daytime temperatures for March. The mean daily maximum temperature for the Territory was 34.7 °C, 0.9 °C above average. Elliot was the only location to have a cooler than normal month with a mean daily maximum temperature of 34.7 °C, 1 °C below average. The Alice Springs District had several hot days near the middle of the month (the hottest day in the NT was at Alice Springs Airport with 40.9 °C on the 15th) but the beginning and end of the month were near normal across the south of the NT.

Temperatures across the Top End of the NT were generally warmer than normal. This was due to a lack of persistent cloud cover and rainfall in what is usually a rainy month. The warmest days on average were at Bradshaw with 37.3 °C and there were several high temperature records set along the north coast. Channel Point, Point Fawcett and Dum-In-Mirrie were among the sites to see their highest March temperature on record while Mango Farm and Middle Point had their highest March mean daily maximum temperature on record.

Minimum temperature

The Territory as a whole had a mean daily minimum temperature of 21.4 °C, 0.3 °C below average. Portions of the Victoria River District and the northern Alice Springs District saw mean daily minimum temperers that were slightly lower than normal while along the southern border minimum temperatures were, generally, warmer than normal.

A few days with low humidity allowed the overnight temperatures across the tropical north to be the lowest on record on the 27th and 28th. Many locations experienced minimum temperatures similar to the dry season, these include: Daly Waters with 11.4 °C on the 27th, Tindal RAAF with 14.5 °C on the 27th, Batchelor with 15.5 °C on the 28th and Jabiru with 19.5 °C on the 27th.

Darwin and surrounding region

March 2014 was a dry month for most of the Darwin region. Darwin Airport ended the month with only 92.2 mm for the month—this is the second lowest March rainfall on record with the lowest being 88.0 mm in March 1978. The Chase, in Palmerston, also had the second–driest March on record with only 68.2 mm. Further inland, Middle Point ended the month with only 94.6 mm–also ranking it as the second driest March on record with the record of 69.8 mm occurring in 2010. Leanyer set a new record for the driest March on record with 83.4 mm (previous record was 99.6 mm in March 2003) as did Channel Point with 82.7 mm (previous record was 108.8 in March 2009).

Both maximum and minimum temperatures were near average for most of the Darwin Region. A lack of cloud cover in a typically rainy month caused monthly maximum temperatures to be generally higher than normal, while dry air allowed overnight minimums to drop to near or a slightly below normal. Darwin Airport hada mean daily maximum temperature of 33.0 °C, 1.1 °C above average. The mean daily minimum temperature at Darwin Airport was 24.7 °C, 0.2 °C above average.

Notes

A Monthly Climate Summary is prepared to list the main features of the weather in Northern Territory using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at
6 pm on Tuesday 1 April 2014.
Some checks have been made on the data, but it is possible that results will change
as new information becomes available.

Averages are long-term means based on observations from
all available years of record, which vary widely from site to site.
They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site,
based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9
and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.